Improvement in metal plow-beams



NITED STATES PATENT Orrrcn MALCOLM MGDOWELL, OF BAVENSWOOD, ILLINOIS.

IMPROVEMENT IN METAL PLOW-BEAMS.

Specification forming part of Letters Patent N0. 158,725, dated January 12, 1875; application filed October 1, 1874.

To all whom it may concern:

Be it known that I, MALCOLM McDowELL, of Ravenswood, Cook county, State of Illinois, have invented a Metal Plow-Beam, of which the following is a specification:

My metal plow beam may be made of wrought-iron or wrought-steelcastiron or cast-steel, or of malleable iron'. What I prefer, and of which I make them, is wrought cast-steel.

The beam is made of a bar of metal, the mid cross-section of which is an inverted T, and so tapered and formed as to give it the required strength, with greater lightness and gracefulness of shape and form as compared with the ordinary cast or wrought iron beam.

To better describe the beam, it may be divvided into three sections-front or clevis end, that part lying between the lines A B and C D; the inid-section, that part lying between A B and E F 5 and the land-side or rear end the remainder. The clevis end is that part of the plow-beam to which the horses are hitched; the mid-section, that part of the plow-beam to which the mold-board is attached; and the land-side or rear end is that part to which is made fast the landside of the plow.

By referring to the accompanying drawings, Figure 1 is a top view of the beam when straight. Fig. 2 is a side elevation of the beam when straight. Fig. 3 is a side elevation of the beam when formed and shaped. Fig. 4 is an end view ot beam when formed, showing the set-off in the Vland-side or rear end, which may be reversed, and make the plow-beam either for a right or left hand plow. Fig. 5 gives a full-sized View of the section at A B, showing a base one and three-fourths by three-fourths, and a web one and three-fourths by three-fourths to seven-sixteenths. Fig. 6

gives a full-sized view of the section at G D,

showing the taper from the full size of the cross-section at A B to C D, showing a taper both in the base and web of the beam, gradually reducing the section in thirty inches on the clevis end.

By referring to Fig. 1, that part of the beam lying between A B and E F, the lines are all parallel. This is the mid-section, to which the mold -board is attached, and on which the strains are made, and requires it to be full strength, while the remainder of the beam, the land-side or rear end, is tapered only in one direction, and is increased in width in the other, in order to give greater length of bearing along on the land-side of the plows. This end may be tapered as is th'e other clevis end, and made fast to the plow in a sleeve or socket. The beam can be increased in weight or correspondingly increased in strength by increasing the area of the cross-section at A B, and reduced likewise by reducing this cross-section. This form of section of an inverted T gives us both vertical as well as lateral strength, and by taperin g this section I secure the strongest beam for the purpose, with the least amount of metal.

What I cla-im is- A metal beam Jfor plows ofthe cross-section ot' an inverted T, tapering toward the clevis end of the beam, both in the base and web, and also tapering toward the land-sideor rear end, the base diminishing and the web increasing in width until they form a plate of uniform thickness, with dimensions of area equal to that of the mid cross-section, substantially as shown and described.

'MALCOLM McDowELL.

Witnesses:

FRANK RroGMoND, FRANK X. KINZIE. 

